Apparatus for  burning powdered euel



P. A. LEONARD. M. F. MALONEY AND E. FRANDRICH, FLUID PRESSURE APPARATUS ron BURNING POWDERED FUEL.

APPLICATION FILED APR. 2. I918.

1,3@5,?Q@. Patented J 11110 3, 1919.

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FLUID PRESSUR RATUS FOR. BUR POWDERED FUEL. APPLICATION men APR. l8-

Patented J me 9.

FaG- 2? I 3 SHEETS-SH INVENTORS I RANDRICH. FLUID PRESSURE APPARATUS FOR BURNING POWDERED FUEL.

. F. MALONEY AND E,

P. A. LEONARD. M

APPLICATION FILED APR-2. I918.

H J 0 m m P n, I C I z WITNESSES PATRICK A. LEONARD, MICHAEL F. MALONEY, AND ERNEST FAN'DRICH, OF SGHENECTADY, NEW YORK.

FLUID-PRESSURE APPARATUS FOR BURNING POWDERED FUEL.

Specification of Letters Patent.

Application filed April 2, 1918. Serial No. 226,262.

To all whom it may concern:

Be it known that we, PATRICK A. LEONARD, MICHAEL F. MALONEY, and ERNEST FAND- RICH, all of Schenectady, in the county of Schenectady and State of New York, have jointly invented a certain new anduseful Improvement in Fluid-Pressure Apparatus for Burning Powdered Fuel, of which improvement the following is a specification.

lhe objects of our invention are to overcome the objections which obtain in prior appliances for burning powdered fuel, in the particulars of conveying, injecting and burning the fuel; to render the manner of using it absolutely safe and free from explosion; to'simplify and cheapen the appliply of oxygen, but has not provided definite means for holding the fuel in suspension until thoroughly and uniformly mingled with the oxygen and consumed. In most of the prior appliances, the fuel has been forced into the furnace in a stream or streams, either impinging against a refractory surface or being impinged one against another and allowed to follow the draft currents, thus efiecting incomplete admixture of oxygen, imperfect combustion, and consequent waste and loss of eificiency, as well as entailing a greater amount of dust, ash, clinker-s, or sla and forming detrimental deposits of chnkers and slag onthe floor, roof, and walls of the furnace, and also on the contents of Vmetallurgical furnaces, to which they adhere so firmly as to be practically irremovable. In many instances an appreciable portion of the fuel passes through the furnace unconsumed.

e generic operative principle of our in-' vention, by which the highest efiiciency and utmost economy are attained practice, is

that of holding the powdered fuel absolutely in suspension, within the furnace, until all its particles are thoroughly mixed with the supplied oxygen, and entirely consumed, thus rendering the combustion perfect, preventing smoke and dust, and the formation of deposit within the furnace and reducing the amount of the residual clinker or slag to the minimum.

In the accompanying drawings: Figure 1 is a vertical longitudinal central section through a heating furnace for metal billets, illustrating an application of our invention; Fig. 2, a transverse section through the same, on the line at, a of Fig. 1; Fig. 3, a vertical longitudinal section, on an enlarged scale through the outer portion of the fuel hopper and the fuel injector; Fig. 4:, a view, in elevation, of the fuel injector, looking to the right in Fig. 3; Fig. 5, a plan view, and Figs. 6 and 7 partial vertical longitudinal central sections, on a further enlarged scale.

Referring descriptively to the specific embodiment of our invention illustrated in the drawings, and applying the term furnace as designating, generically, any receptacle Patented June 3, 1919.

for the consumption of fuel, whether a metallurgical furnace, boiler furnace, or boiler firebox, our invention is exemplified, in Figs. 1 and 2, as applied in connection with a metallurgical furnace for heating billet's, which, in and of itself, is of the ordinary form, inclosing a heating chamber 1, having a hearth, "1, door opening 1", and discharge flue or stack, 1, controlled by a valve or damper, l. Two twyers, 2, 2, are fitted in opposite openings in the side walls of the furnace chamber, said twyers being in line axially and located in a horizontal plane, so that the currents discharged therefrom into the furnace chamber shall impinge directly one against the other. An air blast pipe, 3, leads from a blower or other source of air under pressure into each of the twyers, said pipes being controlled by blast gates, 3 in the ordinary manner.

A fuel hopper, 4, is supported in any convenient position relatively to the furnace, and is connected by a suction pipe, 4, opening into it near its bottom and passing through one of its sides, with a fuel injector, 5, (shown more fully in Figs. 3 to 7 inclu sive). which is of the Giflard type, and is provided with a combining tube, 5, which may either be connected by a fuel delivery pipe, 6, with one of the twyers, 2, as shown in Figs. 1 and 2, or be connected directly to one of the blast pipes, 3, as shown in Fig. 3. Communication between the fuel hopper and the injector is controlled'by a fuel regulating valve, 4", fitted in the suction pipe, P, and carrying an arm, f, actuated by an operating rod, 4 which extends to a location within reach of the furnace operator. An air supply pipe or vacuum breaker, 7, of small diameter, controlled by an atmosphere inlet valve, 7, leads into the lower portion of the fuel hopper.

The fuel injector is actuated .by air under pressure, which is supplied through a blast pipe, 5*, leading into the injector above the connection of the fuel suction pipe, at, therewith. The delivery of air from said pipe, and also the delivery of fuel from the suction pipe, 4, to the combining tube, 5*, are controlled by a hollow or tubular secondary regulating valve, 5, fitted to slide in the body of the injector, and fixed on a stem, 5 which passes through a stufiing box, 5 at one end thereof, and is coupled, by an arm 5, and links, 5 5 to an arm, 4 fixed to the fuel regulating valve, 4*. The lower end of the secondary regulating valve is fitted to seat on the top of the combining tube, 5*, and thereby to cut ofi the supply of fuel to said tube from the suction pipe, P, said valve being normally held seated by a spring, 5, bearing on its upper end, The portion of the valve, 5, with which the blast pipe, 5", communicates, through a lateral opening, is provided with a port, 5", (Figs. 6 and 7) which gradually increases in width from top to bottom. When the valve 5, is unseated, as shown in Fig. 6, the pork, 5, is fully open, as is also the fuel regulating valve, 4 and the receiving end of the combining tube, and air from the blast pipe, 5", thereby forces fuel from the fuel hopper and suction pipe into the fuel delivery pipe, 6, and thence into the twyer, 2, into which it discharges, and the furnace chamber.

When the valve, 5, is seated, as shown in Fig. 7, the supply of fuel to the furnace is completely cut off and the port, 5, is slightly open, at its narrow top portion, thereby admitting a small quantity of air under pressure to the delivery pipe, 6. This limited admission of air under pressure performs the important function of thoroughly cleaning out all particles of fuel from the delivery pipe, between the injector and the furnace, and thereby effectually preventing back firing, which is a common occurrence in apparatus heretofore used. The safety from explosion thus attained, will be recognized as of substantial advantage, by those familiar with the operation of furnaces burning powdered fuel.

While the disposition of the injector and fuel delivery pipe shown in Figs. 1 and 2, in

which the fuel delivered by the injector is conveyed directly to the twyers, has been found in practice, to operate entirely satisfactorily, with fuel pipes of ordinary length, it may, in some instances where exceptionally long fuel pipes are required, or

where the fuel supply, owing to atmospheric conditions, may become somewhat dampened, be desirable to somewhat enlarge the fuel delivery pipe, and supply an additional volume of blast thereto, below the injector, as shown in Fig. 3, in order to effect the traverse of the fuel supply through the delivery pipes with absolute regularity.

While we have specified air as the blast medium utilized,- oun invention is not limited to its application, as dry steam or other gas under pressure may be employed, if desired.

In the operation of an apparatus for burning powdered fuel, of the construction substantially as above described, a jet of powdered fuel, combined with the necessary supply of oxygen contained in air under pressure which is mingled with said jet, impinges directly against an oppositely directed jet of oxygen contained in air under pressure, with the result of thoroughly commingling the particles of fuel with the oxygen of the air, and holding them in perfect suspension in the furnace chamber until entirely consumed. The provision of the air supply pipe, 7, prevents the formation of a partial vacuum, in the fuel hopper.

The characteristic novel feature of ourinvention, and that by which it is, so far as our knowledge and information extend, particularly distinguished from the prior art, consists in means for effecting the combustion of the fuel while in a state of suspension, by applying a blast of air in direct opposition to a blast of commingled fuel and air.- The air blast performs, principally, the mechanical function of holding the supplied fuel in suspension in the furnace, while, of course, at the same time performing the chemical one of providing a supply of oxygen for the support of combustion. The leading function of the opposed blast of commingled fuel and air is the mechanical one of conveying the fuel to a locus of combustion within the furnace, at which it is held in suspension by the air blast and consumed. The air which is mingled with the fuel also acts, in a minor degree, to contribute a modicum of oxygen for supporting combustion. The substantial and material operative advantage incident to the provision of the means aforesaid, is the capacity of independent regulation of the volumes of fuel and air supply, whereby the relation of the fuel suspending blast to the fuel supplying blast, proper for the performance of their respective functions, is maintained under the varying conditions of the operation of the furnace.

structed from direct impingement against,

said first specified jet. v

2. The combination, with a furnace, of two air blast pipes, opening, in line axially thereinto, on opposite sides of its middle plane, and unobstructed intermediately; means for forcing a jet of commingled powdered fuel and air into one of said pipes; and means for delivering a jet of air under pressure into the other pipe.

.8. The combination, with a furnace, of two air blast pipes, opening in line axially thereinto, on o posite sides of its middle plane, and uno' tructed intermediately; a

fuel hopper; an injector; a suction pipe leading from the fuel hopper to the injector; and a connection from the combining tube of the injector to one of the air blast pipes.

4. The combination, with a furnace, of two air blast pipes, opening, in line axially, thereinto on opposite sides of its middle plane, and unobstructed intermediately; a fuel hopper; an injector; a suction pipe leading from the fuel hopper to the injector; a connection from the combining tube of the injector to one of the air blast pipes; and means for preventing the formation of a vacuum in the fuel hop-per,

5. The combination, with a furnace, of two air blast pipes, opening, in line axially, thereinto, on opposite sides of its middle plane, and unobstructed intermediately a fuel hopper; an injector; a suction plpe leading from the fuel hopper to the injector; a connection from the combining tube of the injector to one of the air blast pipes; and an air inlet opening into the fuel opper.

6. The combination, with a furnace, of two air blast pipes, located, in line axially,

thereinto, on opposite sides of its middle plane, and unobstructed intermediately; means for delivering powdered fuel into one of said air blast pipes; and means for delivering an air blast to the pipe which receives the fuel upon the cessation of fuel supply thereto.

7. The combination, with a furnace, of two air blast pipes, opening, in line axially, thereinto, on opposite sides of its middle plane, and unobstructed intermediately; a

fuel hopper; an injector; a suction pipe leading from the fuel hopper to the injector;

.a manually operable valve controlling said pipe; a connection from the combining tube of the injector to one of the air blast pipes; and means for delivering a jet of air from the injector to the connected air blast pipe coincidently with the closure of the manually operable valve.

8. The combination, with a furnace, of two air blast pipes,opening, in line axially, thereinto, on opposite sides of its middle plane, and unobstructed intermediately; a fuel hopper; an injector; a suction plpe leading from the fuel hopper to the injector; a manually operable primary regulating valve controlling said pipe; a connection from the combining tube of the injector to one of the air blast pipes; a secondary regulating valve connected to the primary regulating valve and adapted to close communication between the suction pipe and the combining tube of the injector, said valve having an always open passage to the air supply of said tube; and a high pressure supply port, of gradually increasing area, which is slightly opened by said secondary valve, when the latter is seated, and fully opened when it is unseated.

Witnesses:

W. S. FRAME, JOHN L; STEELE. 

